Nonrefillable cartridge fuse and element



Oct. 15, 1935. J. B. GLOWACKI 2,017,490

NONREFILLABLE CARTRIDGE FUSE AND ELEMENT Filed March 5l, 1954 2 Sheets-Sheet l E v1 L im I m 7 #7 /0 i 275-7 MEUEEQ f/777,25 /azffcz.

.Qcts 15, 1935. I J, B GLOWACK] 2,017,490

NONREFILLABLE CARTRIDGE FUSE AND ELEMENT Filed March 51, 1934 2 sheets-sheet 2 Patented Oct. 15, 1935 NONREFILLABLE CARTRIDGE FUSE AND ELEMENT John B. Glowacki, Chicago, Ill.

Application March 31,

21 Claims.

This invention relates to a non-reiillable cartridge fuse and element and pertains to a type of fuse which must be completely replaced upon the blowing of a fuse element. The improved fuse consists of an insulation casing having end caps secured thereon for securely hol-ding fuse element supporting cups and closure discs in engagement with the end portions of the insulation casing with the fuse element rigidly secured to the inner ends of the cups and completely im-A bedded in a fibrous or granular insulation packing which fills both the casing and the fuse element supporting cups.

it is an object of this invention to provide a non-rellable cartridge fuse including in combination an insulation casing and metal end caps which enclose a fuse element which is mounted to project through a series of different compartments each of which is filled with a packing of insulation material.

It is also an object of this invention to provide a non-rellable cartridge fuse containing a fuse element which projects through different compartments provided Within the fuse and is imbedded in different kinds of insulation packing which fills the various chambers within the fuse.

It is a further object of this invention to provide a non-refillable cartridge fuse wherein the fuse casing contains a lling of insulation material in which a fuse element is imbedded and communicates with circuitously grooved contact discs within the fuse end caps by means of fuse element supporting cups and apertured and grooved closure plates disposed between the cups and the contact discs within the fuse caps.

It is also an object of this invention to provide a non-refillable cartridge fuse having a fuse clement mounted therein with the middle or main body portion of the fuse element imbedded in a lling of insulating material while the ends of the fuse element are imdedded in fillings of insulating material of a different kind from that which surrounds the main body portion of the fuse element.

It is an important object of this invention to provide a non-refillable cartridge fuse and element wherein an insulation casing contains a fuse element which is imbedded in an insulation filling of granular or fibrous material said element having the end portions thereof supported end cups filled with insulating material and acrimed by means of apertured and grooved end plates which are securely held in position by metallic end caps containing circuitously grooved 193.4, Serial No. 718,418

and knurled contact members permitting the slow escape of the products of combustion into cap chambers which are lled with a porous material or with layers of wire screen.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings. Y

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure l is an elevational View of a non-refillable cartridge fuse embodying the principles of this invention.

Figure 2 is an enlarged fragmentary detail longitudinal section taken through the fuse with the fuse element shown in elevation.

Figure 3 is a longitudinal detail section of the fuse taken on line III-III of Figure 2 with the fuse element and end contact members shown in elevation.

Figure 4 is an enlarged plan View of one of the contact discs removed from the fuse showing the network of escape grooves and the corrugated periphery of the contact member.

Figure 5 is a transverse section of the fuse taken on line V-V of Figure 2.

Figure 6 is a top plan view of one of the retaining and closing discs for the casing end cups, removed from the fuse.

Figure 7 is a transverse detail section taken on line VII- VII of Figure 2.

Figure 8 is a transverse detail section taken on line VIII--VIII of Figure 2, disclosing the means for rigidly clamping the end caps on the fuse casing.

Figure 9 is a longitudinal sectional View similar to thatV illustrated in Figure 3 covering a fuse having mounted therein a modified form of fuse element.

Figure 10 is a plan view of the modied form of fuse element shown in Figure 9.

Figure ll is a side View of another modiiied form of fuse element wherein both ends of the fuse strip project into the slotted inner ends of the fuse strip mounting posts.

Figure 12 is a fragmentary side elevation of still another modiiied form of fuse element including fuse element posts connected by a fuse wire. Figure 13 is a fragmentary longitudinal section through one end of another modilied form of fuse illustrating a modified form of end cap containing modified forms of a casing closure cup and a modified form of contact disc for holding a porous or screen filling within the apertured outer end of the fuse cap.

Figure 14 is an outer end view of a casing end cap of the type shown in Figure 13, removed from the fuse.

As shown on the drawings:

The non-refillable cartridge fuse comprises an insulation sleeve or casing I having the main or middle chamber thereof filled with a filling or packing of a flreproof or insulation material 2 such as shredded or fibrous asbestos in a substantially loose form or any suitable kind of granular insulating material.

Disposed longitudinally within the casing I and imbedded by the insulation filling or packing 2 is a fuse element comprising a main fuse strip 3 having pairs of oppositely positioned. notches 4 provided in the longitudinal margins thereof. Also provided in the fuse strip 3 between the pairs of longitudinal notches 4 are irregular slots 5 leaving narrow fusing strips or sections 6 disposed between the notches 4 and the slots 5. The fuse element is provided with integral tapered end pieces 'I the inner ends of which are of a width less than the width of the main body portion of the fuse element to provide stop shoulders 8 as clearly illustrated in Figure 2.

Tightly projecting into each end of the fuse casing I is an end closure cup 9 constructed of brass or other suitable metal and having the inner end thereof closed by means of an integral closure plate or disc IIJ having a circular row of outlet or vent openings or apertures I I provided therein around a middle vent opening I2. Intersecting the middle vent opening I2 is a diametrical slot I3 through which a tapered end I of the fuse element projects limited by the stop shoulders 8 of the fuse element. Integrally formed on the outer end of the closure cup 9 is an outwardly directed stop flange I4 which seats against the outer end of the fuse casing I and limits the insertion of the cup 9 into the casing as clearly illustrated in Figure 2.

Seated within each of the end cups 9 adjacent the inner surface of the apertured end plate I0 o1' the cup is a soft asbestos washer or plate I5 provided with a diametrical slot which intersects a middle aperture or opening I1 as clearly illustrated in Figure 8. The slot I6 is provided to receive the tapered end 1 of the fuse element. The slot I6 registers with the slot I3 provided in the end plate il) of the cup 9.

The interior of each of the casing closure cups 9 is filled with a filling or packing of shredded or fibrous soft asbestos or other suitable fireproof insulating material I8.

For the purpose of properly holding the fuse element longitudinally positioned centrally within the fuse casing and for holding the casing closure cups 9 in place the shouldered portions of the fuse element are soldered or otherwise rigidly secured to the cup end plates I0.

The packing I8 in each of the closure cups 9 is retained in place by means of a brass closure or retaiing disc or plate I9 having the central portion depressed amount substantially equal to the thickness of the plate I9 to form a raised crown portion or cup-shaped boss 2D having a central aperture 2I. Struck downwardly from the boss 2i! are a plurality of radially positioned V-shaped cutlet or Ventilating grooves 22 the inner ends of which terminate in the central opening 2I. The outer ends of the recess ventilating grooves 22 terminate in the periphery of the boss 2U which is formed on the closure disc I9.

Engaged on each end of the fuse casing I for the purpose of enclosing the closure plate I9 and the casing end cup is a metal end cap 23 open at one end and closed at the opposite end. The closed end of the cap 23 is provided with a hood 24 the end surface of which is provided with an escape or outlet opening 25. The hood 24 affords a gas escape chamber which is filled with a porous filling such as a stack of superimposed wire screen discs 26 which contact the inner surface of the apertured end plate of the cap hood 24 as clearly illustrated in Figure 2. The lling or packing of wire discs 26 is held in position within the chamber of the hood 24 by means of a metal contact plate or disc 2'I the outer periphery of which is knurled at 28. The knurling 28 is provided to cut into the inner walls of the closure cap 23 and affords escape passages between the contact plate 21 and the inner walls of the cap 23. The outer face of the contact disc or plate 21 is provided with a network of escape grooves or passages 2Q, the grooves of which intersect one another and communicate with the openings provided in the porous filling or wire screen discs 26 which fill the cap hood 24. To assist in holding the contact disc or plate 21 secured in the closed end of the casing cap 23 the contact plate may be staked at 30 (Figure 2) to project into the material forming the inner walls of the casing end cap 23.

For the purpose of rigidly holding the end cap engaged on the end of the fuse casing I against rotation and against removal the end of the fuse is engaged in a suitable punch machine and has pairs of lugs or indents 3I struck inwardly therefrom to cut into the fibrous material of the fuse casing I as clearly illustrated in Figure 8. Attention is called to the fact that during the time the indents 3I are struck inwardly from the fuse caps 23 the end cups 9 engaged within the ends of the fuse casing I serve as supports or bracing means for the casing to prevent breaking or bending of the inner surfaces of the casing end sections when the end caps 23 are secured in position to close the ends of the fuse casing.

Figures 9 and 10 illustrate a modified form of fuse element for use in connection with a cartridge type fuse of the kind illustrated in Figures 1 to 8 of the drawings. The modified form of fuse element comprises a fuse strip 32 having rounded end pieces 33. Formed in the longitudinal margins of the fuse strip 32 are pairs of oppositely positioned notches 34. Also provided in the body portion of the fuse strip 32 are irregular openings or slots 35 which are positioned between the pairs of notches 34 to form narrow fusing strips 36. The end portions 33 of the fuse strip are slightly deflected and are soldered or otherwise rigidly secured to opposite sides of a pair of copper terminal posts or mounting stems 3l the inner ends of which are spaced apart and are connected by the diagonally positioned intermediate or middie portion of the fuse element 32. Integrally formed around each of the fuse mounting posts or stems 3l a short distance from the outer end thereof are a plurality of stop lugs or beads 38.

When the fuse element unit of the type illustrated in Figure 10 is mounted Within a fuse as shown in Figure 9 the mounting posts have the end portions thereof projecting through the middie apertures I2 of the cup bases I0 and through the middle openings in the insulation washers I5 so that the end portions of the mounting posts are imbedded in the insulating filling or packing i8 contained within the fuse end cups 9. The fuse element mounting posts 31 are soldered to the base plates I0 of the fuse cups 9 to hold the fuse element unit disposed longitudinally within the fuse casing and completely imbedded in the insulation filling or packing contained within the casing l and within the end closure cups of the casing.

Figure ll illustrates another modified form of fuse element unit with the parts constructed similar to the parts of the fuse element illustrated in Figure 10 with the exception that the end portions 33 of the fuse element strip are secured in slots provided diametrically in the inner ends of the fuse element supporting posts or stems 31.

In the modified form of fuse element unit illustrated in Figure l2 a fuse wire 39 has the ends thereof projecting axially into axial openings in the inner ends of a pair of mounting posts or stems 4t having stop lugs or beads 4l integrally formed around the same a short distance from the ends of the` posts.

Figures 13 and 14 illustrate a non-rellable cartridge fuse comprising an insulation casing 42 for supporting therein a fuse element imbedded in insulation packings similar to the construction illustrated in Figure 2. Each end of the fuse casing 42 is closed by means of an end cup 43 which projects into the end of the casing and has the inner end thereof closed by means of a. closure plate 44 provided with a plurality of vent openings f1.5. The end plate 44 is provided with a middle opening 4B which is intersected by a diametric slot 41. The slot 41 is provided for the reception of the tapered end 1 of a fuse element to allow the end portions 1 to project into the cups 43 to be imbedded in a filling of insulating material i8 such as is illustrated in Figure 2 of the drawings. Integrally formed on the outer end of the closure cup 43 is an outwardly directed flange 48 which is provided with a plurality of radially positioned spaced slots 49 which continue inwardly and then downwardly into the wall of the cup 43 as clearly illustrated in Figure 13. Engaged over the end of the casing 42 and rigidly secured thereto by staking, similar to the arrangement illustrated in Figure 8, is an end metal closure cap 58 provided with an integral end closure plate 5i provided with a passaged neck or boss 52 the passage 53 of which communicates with the interior of the cap. Disposed within the closed end of the cap adjacent the inner surface of the end closure plate 5I is a filling or packing consisting of a porous material such as a plurality of layers oi superimposed wire screen discs 54. The screen packing 54 is rigidly held in place by means of a metal contact disc or plate 55 which is secured within the cap 5l) by means of staking `or other suitable means. The contact disc 55 has the peripheral surface thereof knurled at 56 to afford a plurality of escape grooves between the chamber provided within the casing end closure cup 43 and the gas and hot air outlet chamber of the closure cap 53. The contact disc 55 seats tightly against the iiange 48 of the casing closure cup 43 to rigidly hold the cup in position.

When an improved type of non-rellable cartridge fuse of the type hereinbefore described is mounted in an electrical circuit and an excess current or a short circuit develops the narrow fusing strips 6 of the fuse element 3 will blow to break the circuit. The hot metal resulting from the blowing of the narrowdfuse strips 6 is permitted to imbed itself in the insulation filling 2,

while the hot air and gases resulting from the blowing of the fuse element spread through the openings provided in the insulation filling 2 and pass out of the main portion of the casing l through the Vent openings Il provided in the 5 inner walls l0 of the casing closure cups 9. From the openings Il the hot air and gases come into contact with the insulation washers or discs i5 and after passing through the pores thereof enter the insulation packing I8 which fills the cup 10 chambers. The hot air and gases escape from the cups 9 through the openings 2l in the closure discs or plates l 9 and pass through the V-shaped grooves 22 into the space provided in the fuse caps 23 between the closure plates or discs I9 l5 and the contact plates or discs 21. From the spaces provided in the end closure caps 23 the hot air and gases escape through the knurling grooves provided in the peripheries of the contact discs 21 and enter the circuitous network of pas- 20 sages 29 provided in the outer surfaces of the contact discs 21 and move into contact with the porous fillings or wire screen packings 26 contained within the chambers of the hood portions 24 of the fuse closure caps. By the time the hot 25 air and gases resulting from the blowing of the fuse element reach the escape openings 25 in the end plates of the hood portions 24 of the fuse closure caps the speed of the hot air and the gases is greatly reduced and the air and gases are cooled off so that there is only a slow substantially noiseless escape of the air and gases from the ends of the blown fuse.

The fuses of this invention are of the non-re-v iillable type so that after a fuse element has been blown it is necessary to replace the entire fuse by a new one.

In the modified form of the fuse illustrated in Figures 13 and 14 it will be noted that the end hood portions are omitted in the construction of 4o the end closure caps 50 and that the filling or packing of wire screen discs 54 is contained directly within the caps and is held in position by the knurled contact discs or plates 55 which also serve as closure means for the flanged ends of the casing closure cups 43. In this form of the fuse the apertured and grooved closure discs I9 of the type illustrated in the fuse shown in Figure 2 are omitted.

It will of course be understood that various details of construction may be varied through a Wide range without departing from the principles of this invention and it is therefore not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A non-rellable cartridge fuse comprising an insulation casing, end cups engaged in the ends of the casing, a fuse element supported by the end cups and disposed longitudinally within the casing, an insulation filling within the casing and within the end cups for imbedding the fuse element, apertured and grooved closure discs positioned adjacent the outer ends of the cups, aper- 55 tured end caps rigidly secured on the ends of the casing, grooved contact plates secured in the caps and in contact with the apertured and grooved closure discs, and porous fillings within the closure caps held in position by the grooved contact plates.

2. A non-refillable cartridge fuse comprising .an insulation casing, apertured and slotted end cups engaged in the ends of the casing, a fuse element supported by the cups and disposed longitudinally Within the casing, an insulation fllling in the casing and in each of the cups for imbedding the fuse element, apertured and grooved closure discs positioned against the outer ends of the cups, and cap units rigidly secured on the ends of the casing and clamping the closure discs against the outer ends of the cups.

3. A non-reflllable cartridge fuse comprising an insulation casing, apertured and slotted metal cups projecting into the ends of the casing, a fuse element projecting into the cups and soldered thereto with the main body portion of the fuse element disposed longitudinally within the insulation casing, a porous insulation filling in the casing and in the end cups for completely imbedding the fuse element, apertured and grooved metallic closure discs contacting the outer ends of the cups to close the same, end caps rigidly secured on the ends of the insulation casing, grooved contact plates secured in the caps and in contact with the closure discs to hold the sam'e in position, apertured hoods formed on the ends of the caps, and a porous filling in the hoods in contact with the grooved contact plates.

4. A non-rellable cartridge fuse comprising an insulation casing, flanged apertured metallic end cups projecting into the ends of the 'casing with the flanges of the cups seated against the ends of the casing, a fuse element disposed within the casing and projecting into the cups, a porous insulation filling disposed Within the casing and within the cups to ini-,lied the fuse element, apertured and grooved closure discs contacting the flanges of the cups to close the outer open ends of the cups, and cap units rigidly secured on the ends of the casing to hold the closure discs and said cups secured in position.

5. A non-rellable cartridge fuse comprising an insulation casing, apertured and slotted end cups projecting into the ends of the casing, flanges formed on the cups to seat against the ends of the casing to limit the inward projection of the cups, a fuse element disposed in the casing and projecting into the cups and soldered thereto, apertured closure discs positioned against the outer ends of the cups, apertured and grooved bosses formed on said discs, and cap units rigidly secured on the ends of the casing for holding the closure discs clamped in position.

6. A non-refillable cartridge fuse comprising an insulation casing, apertured and slotted metal end cups projecting into the ends of the casing, insulation washers in the cups for closing the apertures, flanges formed on the outer open ends of the cups and seated against the ends of the casing to limit the inward movement of the cups, a fuse elem'ent disposed in the casing and projecting into the cups and soldered thereto, a

porous insulation filling disposed Within the casing and within the cups to imbed the fuse element and closure cap units rigidly secured on the ends of the casing for closing the outer ends of the casing cups.

7. A non-reflllable cartridge fuse comprising an insulation casing, end cups projecting into the ends of the casing, a fuse element in the casing projecting into the cups and soldered thereto, insulation means in the casing and cups for imbedding the fuse element, end cap units engaged on the ends of the casing, and means struck inwardly from the caps to project into the casing material to rigidly secure the caps in place, said cups serving as braces against the inner surfaces of the casing when said means are struck from the caps into the casing material.

8. A cartridge fuse comprising an insulation casing, metallic cups projecting into the ends of the casing, a fuse element in the casing and secured to the cups to connect the same, a porous insulation filling in the casing and in the cups to imbed the fuse element, caps rigidly secured on the ends of the casing, a plurality of apertured and grooved discs clamped between the caps and the cups, and screen filling m'eans in the caps to the outside of the discs.

9. A cartridge fuse of the class described comprising an insulation casing, metallic end cups projecting into the ends of the casing, a fuse element connecting the cups and secured thereto for holding the same in place, insulating means imbedding the fuse element, closure means for closing the outer ends of the cups, apertured caps rigidly secured on the ends of the casing, grooved contact members in the caps for holding the closure means clamped against the outer ends of the cups, and porous llings in the caps between the ends of the caps and said contact means.

l0. A non-refillable cartridge fuse comprising an insulation casing, apertured cup members projecting into the ends of the casing, insulation Washers disposed in the cups to close the apertures therein, a fuse element disposed in the casing and having the ends thereof projecting into the cups and through the insulation Washers, an insulation filling' in the casing and in said cups to completely imbed the fuse element, apertured and slotted closure discs positioned against the outer ends of the cups to close the same, end caps rigidly secured on the ends of the insulation casing, porous fillings in the caps, grooved contact plates secured in the caps for holding the porous fillings in place and also serving to clamp the closure discs againstthe outer ends of the cups.

11. A non-rellable cartridge fuse comprising an insulation casing, apertured cups projecting into the ends of the casing and having grooved flanges formed thereon seated against the ends of the casing, a fuse element in the casing secured to the cups to connect the same, apertured caps engaged on the ends of the casing, porous fillings in the apertured caps, and knurled contact discs secured in the caps for holding the po rous fillings in place and seated against the grooved flanges of the cups.

12. A cartridge fuse comprising an insulation casing, cups projecting into the ends of the casing, a fuse element in the casing, having end portions projecting into the cups to hold the fuse element supported in position, stop members formed on the fuse element and contacting the cups to limit the projection of the end portions of the fuse element into the cups, insulating means in the casing and cups for imbedding the fuse element, and apertured radially grooved discs seated on the outer ends or" the cups.

13. A non-rellable cartridge fuse including in combination an insulation casing, flanged apertured cups projecting into the ends of the casing, a fuse element in the casing having the ends thereof projecting into the cups and soldered thereto, a porous insulation filling in the casing and in the cups for completely imbedding the fuse element and the ends thereof, and apertured and grooved closure discs seated against the flanged open ends of the cups to close the same.

14. A non-refillable cartridge fuse including in combination an insulation casing, metallic cups projecting into the ends of the casing, apertured and grooved closure discs seated against the outer ends of the metallic cups, and a fuse unit in the casing comprising a fuse member, mounting posts secured to the ends thereof and projecting into the cups and soldered thereto, and stop members on the mounting posts contacting the inner ends of the cups to hold the fuse member in a predetermined position within the fuse casing.

l5. In a cartridge fuse of the class described the combination with a casing having end caps thereon, of end cups engaged therein, each of said cups comprising a body portion, an insulation filling therein, a ilange integrally formed on one end of said body portion and an apertured and slotted closure plate integrally formed on the opposite end of the body portion.

16. A cartridge type fuse of the class described including in combination a casing end cup comprising a body portion, an apertured and slotted closure plate integrally formed on one end of the body portion and a flange integrally formed on the opposite end of the body portion and having a plurality of radial slots therein which extend downwardly into the body portion.

17. A cartridge fuse of the class described including in combination an insulation casing, a ilanged and apertured metallic cup engaged in one end of the casing, and a closure for said cup, said closure comprising a disc having an aperture therein, a boss integrally formed on one side of the disc and having an aperture therein registering with the aperture in the disc, said boss also having a plurality of radial grooves therein cornmunicating at their inner ends with the boss aperture.

18. A cartridge type fuse of the class described including in combination a cup closure unit comprising a disc having an opening therein, a boss integrally formed on one side oi the disc and having an opening therein registering with the opening in the disc, said boss having a plurality oi grooves therein communicating with the boss aperture and having the outer ends of the grooves opening through the peripheral surface of the boss.

19. A cartridge fuse comprising an insulation casing, cup members projecting into the ends of the casing and contacting the inner surface 0I the casing to serve as braces therefor, a fuse element connecting said cups and supported thereby, closure caps engaged on the ends of the casing, and means struck inwardly from the caps into the casing material disposed between the cups and the caps, said cups bracing the casing material to prevent the breaking through of the casing material resulting from the formation oi said means.

20. A fuse comprising an insulation casing, cups projecting into the ends of the casing and having angcs formed thereon and seated against the ends of the casing, said ilanges having grooves therein extending into the walls of the cups, a fuse element connecting said cups, caps engaged on the ends of the casing, and grooved contact means in said caps seated on the grooved flanges of the cups.

2l. A fuse including in combination a casing, flanged apertured and slotted cups projecting into the ends of the casing, said flanges having grooves therein continuing into the Walls of the cups, a fuse element connecting said cups, and grooved contact means on the casing and contacting said cups.

JOHN B. GLOWACKI. 

